Numerical and experimental study on the effect of nozzle position and inlet air temperature in an industrial-type biomass gasifier

A number of significant parameters such as gasification temperature, dimensions of gasifier, nature of feedstock, position of the components, particle size of feedstock, inlet air temperature, equivalence ratio, and type of gasifier highly influence the yield and characteristics of producer gas (PG). However, structural design of the air nozzle and temperature of the inlet air have received significant attention in enhancing the composition of producer gas and its gasification efficiency. In this study, species transport model of the numerical simulation had been selected to analyze the performance parameters of a gasifier for the air nozzle’s angle and inlet air temperature from 0 to 60° and 27 to 627 °C, respectively. Rice husk was used as the feedstock. For the accuracy of simulation, the results were compared with an experimental study. The combustible gas composition, higher heating value of PG was analyzed in both numerical and experimental studies; furthermore, the prevailing temperature inside the gasifier was also keenly observed and recorded. Among the various nozzle positions, the composition of CO, H2, and CH4 in the producer gas was better at 45° nozzle inclination with 627 °C inlet air temperature; moreover, the composition of the gaseous compounds in the PG were found as 19 to 23%, 13 to 15%, and 2 to 3% respectively. For the above-mentioned conditions of nozzle inclination and inlet air temperature, the calorific value of producer gas was in the range of 4–6 MJ/Nm3. The temperature distribution in the combustion, reduction, pyrolysis, and drying zones was in the range of 1000–1200 °C, 600–700 °C, 300–420 °C, and 200–300 °C, respectively.